Microbial strain data are being entered into a data bank which provides such services as: data on specific organisms and/or groups of organisms, a locator service for strains with special characteritics, identification of unknown isolates, cluster analysis definition of parameters of taxa, data management and report writing aids, aids in quality control, and communication of data via common format. Files of primary data on a large number of microorganisms provide a resource for asking both ecological and epidemiological questions of interest in dental research. Programs are being developed and tested to enter, retrieve, and analyze the data in a variety of ways for epidemiological, diagnostic, taxonomic, ecological, etc. uses. The long term goal is to establish a world-wide data bank at a series of cooperating centers. The system originally developed for bacteria is now being expanded to include the algae, yeasts, molds and protozoa.